The Lieutenant's Key
by Fayolinn
Summary: Levi's aware that Eren's a blue-green eyed kid of 18 years with a key hanging around his neck – but what the lance corporal isn't aware of is the fact that the boy himself may be the key he doesn't know he's looking for.


Levi roamed the halls late at night, white cloth draped over his head and lower half of his face. His thoughts were keeping him awake, preventing sleep from coming easy, so he busied himself by being productive: he cleaned. It was a familiar chore, a natural habit that helped him relax. He needed to be active because if he sat too long, alone with dangerous ideas, he'd lose his sanity.

They weren't dangerous in the sense that they included violence, or something of catastrophic proportions like the destruction of humanity. In fact, these ideas included only two people – Levi being one of them – and they involved not danger, but _intimacy_.

Levi swept the floor of an abandoned room, blinking away the dust. See, Levi had never been intimate with anyone – intimate in the sense of _romance_. Sure, he was intimate with Irwin in the way that he trusted the commander's instructions and judgment and followed it without hesitation. He was intimate with Hanji in the way that her scientific information provided helpful insights for their missions and her enthusiasm provided a light in the darkness.

But then, three years ago, a blue-green eyed boy decided to inadvertently draw attention to himself and land himself behind bars – chained to a bed – and cause Levi to doubt himself. Levi hadn't thought anything of it at the time. Kids were always causing trouble, and just because this particular one could shift into a titan didn't change anything. Kids were also messy, loud, and stupid, so Levi did his best to distance himself away from them as far as possible.

But now this blue-green eyed boy wasn't a kid anymore. He was still occasionally messy, loud, and quite a bit stupid, but somehow that didn't really matter anymore.

With a sigh Levi stowed away the broom, making his way to the next room before remembering exactly who resided within. Pulling the white cloth down over his nose and beneath his chin, Levi leaned against the doorway, silently observing the figure asleep on the bed. The blue-green eyed boy. Eren Jaeger.

Eren was asleep on his back, head tossed to one side and one hand resting by his cheek. He was dressed only in white slacks that cut off around the calf; the sheets were tangled around his ankles. Levi shook his head, letting out a weary breath. Was it really necessary to sleep shirtless? It was a miracle Eren hadn't acquired a cold yet, and the only thing worse than a messy, loud, stupid kid was one that was _sick_.

Shifting his weight off the wall, Levi stepped forward and picked up the sheet with one hand, sliding it over Eren's long legs. No doubt the boy would just kick it off again, but no one could accuse Levi of not trying. His hand hesitated over Eren's abdominals – when had those begun to show? – as his eyes focused on the key adorning his neck.

Releasing the sheet, Levi gently lowered himself onto the bed. He shouldn't be here, this wasn't wise – hadn't he learned anything from the dangerous ideas that hadn't let him sleep in the first place? – but lately the corporal had discovered that Eren had skill he wasn't even aware he had. Levi hadn't noticed it at first, it was so subtle, but Eren had the ability to crumble Levi's self-restraint.

It was infuriating. Every day, Levi would wake and convince himself he had no attachment to the boy whatsoever – and then Eren would walk into view and suddenly his resolve would collapse. It was like a terminal illness; as the months progressed, it got worse. Levi went from sneaking sidelong glances to masturbating with visions of blue-green eyes. It was disgusting. He was a full-grown man in his early thirties and he was lusting after a child half his age.

Well, said child was now legal, but it didn't help that Eren could also be labeled as the first person Levi had ever yearned for.

Levi passively noted the way Eren's dark eyelashes curled, the smudge of dirt on his cheekbone, the way his lips parted just ever so slightly. The curve of his jawline, the vulnerable tendons in his neck, the sharp contours of his collarbone. The steady rise and fall of his bare chest. Levi's attention fell on the golden key again, just above Eren's heart.

The corporal reached out, fingertips lightly brushing warm skin before picking up the key. Eren kept the key with him at all times as an inseparable, inanimate companion. Levi turned the object over between his fingers, studying it closely. He had never been able to examine it at such close proximity before, and though the darkness made it difficult to admire its finer details, Levi could still tell it had a specialized design.

"Your touch is surprisingly warm, _heichou_."

Levi dropped the key immediately; it thudded dully against Eren's chest.

"Ow," he said.

Levi recovered and scowled. "Do not exaggerate, that did not hurt."

"No, but the way you're frowning at me hurts my feelings." Eren smiled sleepily, stretching his arms above his head and Levi most certainly did not watch the way his muscles flexed fluidly. "May I ask why I'm granted the honor of a late-night visit?"

Levi raised his chin in almost child-like defiance. "May I ask why you desire to sleep without a shirt?"

Eren quirked an eyebrow; he could certainly play this game. "May I ask why you're interested?"

Levi tugged the cloth tied around his neck loose and stuffed it in Eren's face.

"Sorry, sorry, I know how you hate having your sass thrown back at you— _ah-ah-ah_, stop! I really am sorry!" Eren was forced to yield as Levi twisted his arm behind his back, forcing him onto his side. When he was satisfied Eren was fully submissive, he released his hold, watching as Eren wiped away involuntarily tears and rubbed his sore arm.

"As much a brat as ever," Levi muttered. Were his standards really this low?

Eren pouted, propping himself up on his elbows. "In my defense, I asked first."

Levi narrowed his eyes, realizing Eren was right. "I was cleaning," he admitted, which was whole-heartedly the truth, "and I noticed you had kicked off your sheets. Again."

"Again?" Eren rubbed his hair in an annoyingly attractive way. "No wonder it's so cold in the mornings."

"Idiot. And now you must answer my question."

Eren tilted his head, eyes bright and expression unusually serious. "Only if you answer my second question afterwards."

"Don't push your boundaries, brat."

With a shrug, Eren pushed himself up into a sitting position. "I had spilled milk on it during dinner. Also, sometimes my skin randomly feels hot and wearing a shirt just gets too uncomfortable. Might be a titan-shifter thing." He blinked at the corporal, clearly brimming with questions judging by the way he subconsciously (and irritatingly) bit his lip. "True story," he added lamely.

Levi nodded absently, trying his best to look away. He could feel it, feel his self-restraint dissolving at an alarming rate; he needed to leave immediately if he were to preserve his dignity and pride. Eren was off-limits, he had done his best to persuade himself this, he didn't need—

"Levi-_heichou_?" Eren was dangerously close now, leaning forward with concern. "You look kinda pale. Might be the moonlight, but are you feeling alright?" He raised his hand, resting the back of it against Levi's forehead.

That was the straw that broke the camel's back. With a soft snarl, Levi rose, planting his palms on Eren's shoulders and pinning the boy flat on his back. Eren's breath was knocked from his lungs, blue-green eyes wide with shock.

"H-Heichou?"

Levi began to quiver, ebony bangs falling into his eyes as he ducked his head. "D-damn you," he whispered shakily, fingernails digging into skin. "Why… why _you_?"

Eren lay perfectly still, breathing evenly through his nose. "Levi…"

"_Don't_—!" _Don't call me that_, was what he wanted to say. What he _should_ say. Eren was still his subordinate, Levi his superior, he had no right to skip formalities… but what scared Levi was that he _wanted_ Eren to call him that, wanted to hear his first name on those youthful lips.

Why _did _it have to be this boy? This furiously incompetent, overly-determined German brunette with eyes that betrayed his every emotion had somehow managed to awaken feelings Levi wasn't aware he was capable of feeling. The corporal grit his teeth as he shut his eyes, trembling. Why was his heart beating so madly? He felt light-headed and dizzy and ready to pass out.

Be it fate or pure dumb luck, Eren was key to all this. No, he _was_ the key.

Levi felt Eren finally shift beneath him, firm hands encircling his wrists and resting his hands on warm, bare skin – _Eren_'s skin. Levi resisted weakly, shaking his head as the firm hands tenderly slid up his neck, cradling Levi's jaw, and that's when he finally accepted defeat. Levi melted into the touch, helpless and seeking guidance. Eren came to his aid and Levi blindly followed, too afraid to open his eyes else Eren disappear if eye contact was made.

Eren's breath fluttered against his cheek and Levi automatically parted his lips, whining quietly with want. Eren fulfilled his desire and pressed his lips to the corner of Levi's mouth, testing the waters. Levi's lashes brushed Eren's cheek as he turned his head, capturing the boy's bottom lip between his teeth. His fingers involuntarily flexed against Eren's chest, hyperaware of his heartbeat, almost perfectly in sync with Levi's own racing pulse.

"Heichou," Eren crooned into their next kiss, a hint of desperation laced in his voice.

Levi made a disapproving sound, sliding one hand to the back of Eren's neck and a knee between Eren's thighs. "Not—that," he said breathily, deepening the kiss.

Eren compensated, angling his head and granting Levi a better approach. "_Levi_," he whispered wantonly, leaning back onto the bed and bringing the older man with him. Levi fell heavily against Eren but stayed pressed chest to chest, heartbeats hammering against each other. Eren smiled against Levi's mouth, holding him close.

Levi had fought so hard against this for so long, but he had been foolish to try avoiding the inevitable. Eren was his key. It had been Eren all along – this loud, messy, maybe not-so-stupid young man with a frightening temper and heart of gold. Gold as the key dangling around his neck, between their beating hearts they had both readily offered up to the king, and now, to each other.


End file.
